1. Field of the Invention
The present invention relates to optical range measurement devices having transmitters and receivers as well as to the necessary optical devices and analysis devices.
2. Description of the Related Art
In optical range measurement devices of this type, windows are basically used to protect the optical and electronic systems. The contamination of these windows is a constant problem. At airports, in particular, it must be possible to ascertain optical ranges, despite the especially heavy contamination resulting from aircraft exhaust.